The U.S. Chemical Safety Board said Wednesday that Chevron Corp. knew for years of a problem with a corroded pipe that caused the fire last year at its refinery in Richmond, Calif.

The August fire at the 245,000 barrel-a-day refinery near San Francisco burned for hours, sending a column of thick, black smoke over the San Francisco Bay and causing an estimated 15,000 area residents with eye and respiratory problems to visit emergency...